This invention relates to battery containers of the general type known from German Patent Document DE 41 16 253.
German Patent Document DE 41 16 253 discloses a battery container for several electrochemical accumulators or battery units, hereafter referred to as "cells" arranged therein. The cell housings of the individual cells, which are electrically connected with one another on the terminal side by means of current bridges, are made of metal so that they have a good heat transmission. This heat transmission is particularly important for the tempering of the cells since the temperature is a decisive criterion for the parameters of the cells. So that the tempering takes place over the whole surface of the cell, bypass ducts are arranged between the flat sides of cells adjoining cell housings, which bypass ducts are bounded by the flat sides of the corresponding cell housings through which a tempering fluid flows. The cell housings are spaced away from one another with respect to their flat sides by spacers made of an electrically insulating material which are arranged in the area of the corners of the cell housings. For supplying the bypass ducts, the battery container also has in its interior an inflow duct fluidly connected with the bypass ducts and an outflow duct arranged on the opposite end of the bypass duct. The mass flow through the bypass ducts supplied in parallel by the inflow duct with tempered fluid must be approximately equal which is why the clear cross-section of the inflow duct is reduced in the flow direction of the fluid flowing through it and the clear cross-section of the outflow duct, which is arranged opposite it with respect to a bypass duct and is fluidly connected with it, is widened in the flow direction.
Despite the advantages of the known battery container, particularly in the case of "breathing cells", thus in the case of cells or electrochemical accumulators which change their volume during the discharge and/or charge, problems occur again and again with respect to the tempering caused by local temperature differences inside the battery container. Furthermore, for accident-related reasons and also for reasons concerning the stability, a metallic container is required as an end container which is generally embedded in the vehicle body in use of the battery cells and battery container on a battery powered vehicle. Therefore, in the case of electrochemical accumulators having metal housings, for reasons of insulation, an interior insulating plastic container is used as a battery container which is subsequently inserted into the above-mentioned end container. For the above-mentioned reasons, the stability of the overall construction is absolutely necessary. Also, for energy reasons, the total weight of a vehicle must be as low as possible in which case, however, as much electrochemical accumulating capacity as possible must exist in a volume that is as small as possible, and the tempering of the cells must be sufficient. Furthermore, because of the constructional circumstances of the motor vehicle body, the vertical height of the battery container is limited within low tolerances.
It is an object of the invention to further develop a battery container on which the type of this invention is based in that, among other things, the tempering of the cells is improved, in which case, while the advantages of the battery container remain the same, the battery container must have an influence on the overall weight of the motor vehicle which is as low as possible.
In the case of a battery container of the above-mentioned type, this object is achieved by providing spacers between layers of cells, which spacers each have a first portion extending in a vertical direction by an amount corresponding to a vertical thickness of respective ones of said battery cells and a plurality of thin spacing strips extending perpendicular to said first portion and serving to abuttingly engage and space respective flat sides of battery cells stacked on top of one another in the container, said spacing strips defining coolant flow channels along facing flat sides of the battery cells adjacent ones of said spacing strips when in an installed position in said container. As a result of the supporting of the cells housings along at least a large portion of the surface of their flat sides, a uniform cross-section of the bypass duct is ensured also in the case of breathing cells.
Furthermore, this support also contributes to the stabilization of the floor structure of the vehicle body and thus, among other things, to an increase of safety in the case of a crash. Also, the whole battery container is stabilized with respect to a low weight requirement, in which case particularly the metallic wall--viewed as a whole--also contributes to the minimizing of the weight of the overall vehicle because the battery container according to the invention does not, as previously, have to be immersed in an additional sheet metal trough.
A special advantage is also the flat bearing of the cells because, thereby, a new layer of cells has a shorter course in the vertical direction. As a result, an increase of the overall capacity of all cells arranged in the battery container can take place with a slight increase of the vertical height of the battery container. In advantageous cases, that is, in the case of an exchangeable battery container, this may take place within specific limits without changes on the body of the motor vehicle since only the battery container has to be changed.
In addition, when cells are to be cooled, the battery container according to the invention also has the advantage that the wall of the battery container is made of metal so that a cooling can also take place by means of the wall.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.